MBean Notifications

All AMX MBeans that emit Notifications place a java.util.Map within the UserData field of a standard
JMX Notification, which can be obtained using Notification.getUserData(). Within the map are one or more items, which vary according
to the Notification type. Each Notification type, and the data available
within the Notification, is defined in the Javadoc of the MBean (AMX
interface) that emits it.